June 6, 2006

If you are one who has used the Graph tools in Illustrator to create charts and infographics (displaying numerical data in a visual form), you've undoubtedly expressed some level of discontent with the feature (either in public or private). Aside from the fact that the feature itself hasn't seen much improvement since the Bush administration (Senior, that is), graphs also have a tendency of defaulting their appearance to shades of gray when the graph data is updated. And what client sends graph data that isn't edited later in the process?

What makes this particular issue so touchy is that it appears that there is no rhyme or reason for this behavior. At times, you may customize the appearance of a graph by adjusting colors and the like, and those settings remain intact after you've updated the graph data. Yet, other times, the graph defaults to shades of gray.

Having recently given a live eSeminar for Adobe on how to use Illustrator to create snazzy looking graphs and business graphics (it was entitled Making Numbers Look Good and I'll let you know when Adobe has posted a recorded version online for on-demand viewing), I was determined to learn what was causing this seemingly inconsistent behavior.

So I turned to Teri Pettit for guidance on this, and wouldn't you know it -- there's a method behind the madness after all. Hopefully, the information Teri shares here will help you the next time you need to create a lovely graph or chart.

So in another installment of Teri's Wisdom, here's a peek into what's happening behind the scenes with the graph feature in Illustrator:

Editing objects inside graphs is sort of like having action recording turned on, with the actions being stored with the graph instead of in a separate file. Whenever you change the graph data or graph attributes, Illustrator first creates a new default graph at the location that the graph was first created, as if you had just dragged out the graph tool and entered the data. Then all the "graph actions" (edit history) that were recorded since the beginning of time (i.e., the creation of that graph, including any previous graph it was duplicated from) get played back, complete down to the transforms that moved that graph to where it is now.

Just as not every edit you can do in Illustrator is recordable by actions, not every edit you can do in Illustrator is recordable by graphs. In fact, many fewer are recordable by graphs. So for the most part, if the edit is performed by a feature that was introduced after Illustrator 5, it either entirely ignores graphs, or in some cases the edit is performed but is not recorded. This is because most of the features added since Illustrator 6 use a different plugin architecture and abide by different rules.

Sometimes even when some changes are recordable, if other changes are made that are not recordable, the act of making the non-recordable changes will make some of the recorded changes no longer work. (They are still remembered, but they fail to apply, like playing back an action that can't find the right kind of selection anymore.) When that happens, you can getyour graphs reverting to default.

So the safest way to make sure that your edits to graphs are sticky is to confine yourself to editing them using the parts of the application that were available in AI 5. For example, scaling objects with the Scale tool instead of the Bounding Box or the Transform palette or the Transform Each command, or applying paint styles with the Swatches palette or the Color palette instead of dragging dropping color onto objects.

So if you want to apply effects to graph columns in a way that gets remembered, you have to make a named style, and then apply that named style to the graph columns. (For those who aren't aware, Graphic Styles are a powerful way to store appearances, apply them to objects, and to update and modify those appearances. Graphic Styles are covered in depth in Chapter 3 of Real World Illustrator CS2 - Mordy)

Another good tip to follow is to not try to keep making new graphs by duplicating the same old template graphs for years and years and modifying them. Since the edit history is forever, it can get pretty crufty after editing a graph hundreds of times. If all you are going to change is graph data, that's fine, since data changes aren't recorded as a graph edit. But if you are going to be setting up different column styles and text styles and graph style attributes and transformations, it is cleaner to start fresh than to make extensive edits to an old graph.

As I emphasized in my eSeminar, using Graphic Styles (for appearances) and Paragraph Styles (for text) when creating graphs will make your lives a lot easier. In general, getting used to styles will have a positive impact on all of the work that you do in Illustrator.